1. Field of the Invention
The present invention relates to a light emitting diode and a method of fabricating the same, and more particularly, to a light emitting diode and a method of fabricating the same, wherein the light extraction efficiency is improved by scratching a surface of the light emitting diode by an abrasive using an ultrasonic cleaning apparatus.
2. Discussion of the Background
A light emitting diode (LED), as a representative light emitting device, is a photoelectric conversion semiconductor device having a structure, in which N-type semiconductor and P-type semiconductor are coupled with each other, and is configured to emit light through recombination of electrons and holes.
GaN based light emitting diode has been well known as the aforementioned light emitting diode. The GaN based light emitting diode is fabricated by sequentially laminating a GaN based N-type semiconductor layer, an active layer (or light emitting layer) and a P-type semiconductor layer on a substrate made of a material such as sapphire or SiC.
Recently, light emitting diodes with high efficiency have been expected to replace fluorescent lamps, and more particularly, the efficiency of a white light emitting diode is approaching a level similar to the efficiency of a conventional fluorescent lamp. However, there is room for improving the efficiency of the light emitting diode, and therefore, continuous improvement in efficiency has been more required.
In order to improve the efficiency of the light emitting diode, two principal approaches have been attempted. First, there is an approach for increasing an internal quantum efficiency which is determined depending on crystal quality and epitaxial-layered structure, and the second approach is to increase the light extraction efficiency as all the light generated from the light emitting diode does not totally exit to the outside and a large amount of light is internally lost.